1. Field of the Invention
The present invention relates to a vehicle engine output control method and apparatus adopted when an engine output of a vehicle is controlled to a target engine output.
2. Description of the Related Art
A traction control apparatus is well known as one of control apparatus which control an engine output of a vehicle. In the traction control apparatus, when an acceleration slip of the driving wheels is detected, a slip rate S is controlled to cause a coefficient .mu. of friction between the wheels and a road surface to fall within a maximum range (a hatched range in FIG. 18). The slip rate S is given by [(VF-VB)/VF).multidot.100 (%), where VF is the wheel velocity of driving wheels, and VB is the vehicle velocity. More specifically, when a slip of driving wheels is detected, an engine output is controlled to cause the slip rate S to fall within the hatched range, thereby controlling the coefficient .mu. of friction between wheels and a road surface to fall within the maximum range. Thus, an acceleration slip of driving wheels is prevented to improve acceleration characteristics of a vehicle.